Helicobacter pylori (Hp) is a human pathogen that lives in the gastric mucosa of approximately 50% of the world's population causing gastritis, peptic ulcers, and gastric cancer. An increase in resistance to current drugs has sparked the search for new Hp drug targets and therapeutics. One target is the disruption of nucleic acid production, which can be achieved by impeding the synthesis of 6-oxopurine nucleoside monophosphates, the precursors of DNA and RNA. These metabolites are synthesized by Hp xanthine-guanine-hypoxanthine phosphoribosyltransferase (XGHPRT). Here, nucleoside phosphonates have been evaluated, which inhibit the activity of this enzyme with Ki values as low as 200 nM. The prodrugs of these compounds arrest the growth of Hp at a concentration of 50 μM in cell-based assays. The kinetic properties of HpXGHPRT have been determined together with its X-ray crystal structure in the absence and presence of 9-[(N-3-phosphonopropyl)-aminomethyl-9-deazahypoxanthine, providing a basis for new antibiotic development.
- MeSH
- antibakteriální látky chemie metabolismus farmakologie terapeutické užití MeSH
- bakteriální proteiny chemie metabolismus MeSH
- gastrointestinální nemoci farmakoterapie mikrobiologie patologie MeSH
- Helicobacter pylori účinky léků enzymologie MeSH
- hypoxanthinfosforibosyltransferasa chemie metabolismus MeSH
- hypoxanthiny chemie metabolismus farmakologie terapeutické užití MeSH
- infekce vyvolané Helicobacter pylori farmakoterapie patologie MeSH
- kinetika MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- organofosfonáty chemie metabolismus farmakologie terapeutické užití MeSH
- pentosyltransferasy chemie metabolismus MeSH
- prekurzory léčiv chemie metabolismus farmakologie terapeutické užití MeSH
- sekvence aminokyselin MeSH
- sekvenční seřazení MeSH
- simulace molekulární dynamiky MeSH
- vazebná místa MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PURPOSE: Skin permeation/penetration enhancers are substances that enable drug delivery through or into the skin. METHODS: To search for new enhancers with high but reversible activity and acceptable toxicity, we synthesized a series of D-glucose derivatives, both hydrophilic and amphiphilic. RESULTS: Initial evaluation of the ability of these sugar derivatives to increase permeation and penetration of theophylline through/into human skin compared with a control (no enhancer) or sorbitan monolaurate (Span 20; positive control) revealed dodecyl 6-amino-6-deoxy-α-D-glucopyranoside 5 as a promising enhancer. Furthermore, this amino sugar 5 increased epidermal concentration of a highly hydrophilic antiviral cidofovir by a factor of 7. The effect of compound 5 on skin electrical impedance suggested its direct interaction with the skin barrier. Infrared spectroscopy of isolated stratum corneum revealed no effect of enhancer 5 on the stratum corneum proteins but an overall decrease in the lipid chain order. The enhancer showed acceptable toxicity on HaCaT keratinocyte and 3T3 fibroblast cell lines. Finally, transepidermal water loss returned to baseline values after enhancer 5 had been removed from the skin. CONCLUSIONS: Compound 5, a dodecyl amino glucoside, is a promising enhancer that acts through a reversible interaction with the stratum corneum lipids.
- MeSH
- antivirové látky aplikace a dávkování metabolismus MeSH
- aplikace kožní MeSH
- aplikace lokální MeSH
- buněčné linie MeSH
- cytosin aplikace a dávkování analogy a deriváty metabolismus MeSH
- epidermis účinky léků metabolismus MeSH
- farmaceutická chemie MeSH
- glukosidy chemická syntéza farmakologie MeSH
- hexosy farmakologie MeSH
- hydrofobní a hydrofilní interakce MeSH
- keratinocyty účinky léků metabolismus MeSH
- kožní absorpce MeSH
- kůže účinky léků metabolismus MeSH
- lékové transportní systémy MeSH
- lidé MeSH
- lipidy fyziologie MeSH
- organofosfonáty aplikace a dávkování metabolismus MeSH
- permeabilita MeSH
- theofylin aplikace a dávkování metabolismus MeSH
- viabilita buněk MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Human tuberculosis is a chronic infectious disease affecting millions of lives. Because of emerging resistance to current medications, new therapeutic drugs are needed. One potential new target is hypoxanthine-guanine phosphoribosyltransferase (MtHGPRT), a key enzyme of the purine salvage pathway. Here, newly synthesized acyclic nucleoside phosphonates (ANPs) have been shown to be competitive inhibitors of MtHGPRT with Ki values as low as 0.69 μM. Prodrugs of these compounds arrest the growth of a virulent strain of M. tuberculosis with MIC50 values as low as 4.5 μM and possess low cytotoxicity in mammalian cells (CC50 values as high as >300 μM). In addition, the first crystal structures of MtHGPRT (2.03-2.76 Å resolution) have been determined, three of these in complex with novel ANPs and one with GMP and pyrophosphate. These data provide a solid foundation for the further development of ANPs as selective inhibitors of MtHGPRT and as antituberculosis agents.
- MeSH
- antituberkulotika chemie farmakologie MeSH
- difosfáty chemie metabolismus MeSH
- hypoxanthinfosforibosyltransferasa chemie metabolismus MeSH
- inhibitory enzymů chemie farmakologie MeSH
- katalytická doména MeSH
- konformace proteinů MeSH
- krystalografie rentgenová MeSH
- kyselina 5'-guanylová chemie metabolismus MeSH
- lidé MeSH
- molekulární modely MeSH
- molekulární sekvence - údaje MeSH
- molekulární struktura MeSH
- Mycobacterium tuberculosis účinky léků enzymologie MeSH
- nádorové buňky kultivované MeSH
- nádory plic farmakoterapie patologie MeSH
- organofosfonáty chemie metabolismus MeSH
- prekurzory léčiv chemie farmakologie MeSH
- proliferace buněk účinky léků MeSH
- protinádorové látky chemie farmakologie MeSH
- sekvence aminokyselin MeSH
- sekvenční homologie aminokyselin MeSH
- tuberkulóza farmakoterapie mikrobiologie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Our investigation in the chemistry of nucleoside phosphonates has provided an impressive number of novel structurally diverse compounds. Among them, several potent inhibitors of enzymes of nucleosides and nucleotide salvage pathways were found. The findings obtained in synthesis of nucleoside phosphonates are unique. The nucleoside phosphonates provided several types of monomers for the synthesis of modified oligonucleotides. The first non-silyl protecting group was developed and used in the solid-phase synthesis of modified oligoribonucleotides in the reverse direction. The superior nuclease stability of phosphonate internucleotide linkages, their ability to enhance hybridization together with the ability to elicit RNase H activity may classify these compounds as useful in biochemistry and biology
- MeSH
- biochemické jevy MeSH
- fosforylasy chemie metabolismus MeSH
- inhibitory enzymů chemie metabolismus MeSH
- lidé MeSH
- molekulární konformace MeSH
- nukleotidy biosyntéza chemie metabolismus MeSH
- oligonukleotidy * biosyntéza chemie metabolismus MeSH
- organofosfonáty * chemická syntéza chemie metabolismus MeSH
- ribonukleasy chemie metabolismus MeSH
- toll-like receptory chemie metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
OBJECTIVE AND DESIGN: Tenofovir (TFV) is used in pregnant women as a part of combination antiretroviral treatment to prevent mother-to-child transmission of HIV infection. We aimed to detect whether TFV and/or its prodrug, tenofovir disoproxil fumarate (TDF), are substrates of ATP-binding cassette (ABC) transporters that are functionally expressed in the placenta, namely P-glycoprotein (ABCB1/MDR1), Breast Cancer Resistance Protein (ABCG2/BCRP) and Multidrug Resistance-Associated Protein 2 (ABCC2/MRP2). We employed in-vitro cell-based assays and in-situ animal model to assess possible role of the efflux transporters in transplacental pharmacokinetics of TFV and TDF. METHODS: In-vitro transport assays were performed in MDCKII cells transduced with human ABCB1, ABCG2 or ABCC2. To quantify the effect of these transporters on TFV/TDF transplacental passage, we employed the in-situ model of dually perfused rat term placenta in open and closed setup. RESULTS: In-vitro assays revealed that TDF is a dual substrate of ABCB1 and ABCG2 but not of ABCC2. In contrast, TFV transport was not influenced by any of these transporters. Applying concentration-dependent studies and selective inhibitors, we further confirmed these findings in situ on the organ level; both ABCB1 and ABCG2 limited mother-to-fetus transfer of TDF whereas TFV transplacental passage was not affected by these ABC transporters. CONCLUSION: We propose limited mother-to-fetus transport of both TFV and TDF. While placental transport of TFV is restricted passively, by physical-chemical properties of the molecule, mother-to-fetus passage of TDF is actively hindered by placental ABCB1 and ABCG2 transporters, pumping this compound from trophoblast back to maternal circulation.
- MeSH
- ABC transportéry metabolismus MeSH
- adenin analogy a deriváty metabolismus farmakokinetika MeSH
- buněčné linie MeSH
- krysa rodu rattus MeSH
- látky proti HIV metabolismus farmakokinetika MeSH
- lidé MeSH
- nádorové proteiny metabolismus MeSH
- organofosfonáty metabolismus farmakokinetika MeSH
- P-glykoprotein metabolismus MeSH
- potkani Wistar MeSH
- proteiny spojené s mnohočetnou rezistencí k lékům metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
1. Nucleotide analogues comprise an important class of drugs used in treatment of viral infections but also cancer. These drugs affect the structural integrity of DNA and activate different pathways and processes in the cell and may directly or indirectly influence the drug metabolizing system. Adefovir dipivoxil (AD) and tenofovir disoproxil (TD) are nucleotide analogues approved for the treatment of chronic hepatitis B and/or HIV/AIDS infection. 2. To evaluate the risk of their drug-drug interactions on the level of drug metabolism, an effect of both compounds on cytochromes P450 expression was studied using cDNA microarrays, real-time RT-PCR and immunoblotting. Mice were given intraperitoneally 25 mg/kg of AD or TD, respectively. As a positive control, a combination of prototypic cytochromes P450 (CYP) inducers, phenobarbital and β-naphthoflavone was chosen. 3. The data obtained showed a significant CYP induction in the positive control group, but no clinically significant induction of CYP genes by AD or TD was observed. Our results support the evidence of safety of AD and TD with respect to drug-drug interactions based on enzyme induction. These findings are important as a plethora of new antivirals of different types are being tested and introduced to clinical practice, mostly to be used in combinations.
- MeSH
- adenin analogy a deriváty metabolismus MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- myši inbrední C57BL MeSH
- organofosfonáty chemie metabolismus MeSH
- regulace genové exprese enzymů * MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- stanovení celkové genové exprese MeSH
- systém (enzymů) cytochromů P-450 genetika metabolismus MeSH
- western blotting MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hexadecyloxypropyl esters of acyclic nucleoside phosphonates containing guanine (G) or hypoxanthine (Hx) and a (S)-[3-hydroxy-2-(phosphonomethoxy)propyl] [(S)-HPMP] or 2-(2-phosphonoethoxy)ethyl (PEE) acyclic moiety have been prepared. The activity of the prodrugs was evaluated in vitro against different virus families. Whereas ester derivatives of PEEHx and (S)-HPMPHx were antivirally inactive, monoesters of PEEG, and mono- and diesters of (S)-HPMPG showed pronounced antiviral activity against vaccinia virus and/or herpesviruses. Monoesters of (S)-HPMPG emerged as the most potent and selective derivatives against these DNA viruses. None of the compounds were inhibitory against RNA viruses and retroviruses.
- MeSH
- antivirové látky chemická syntéza chemie metabolismus farmakologie MeSH
- buněčné linie MeSH
- DNA viry účinky léků MeSH
- guanin analogy a deriváty chemie MeSH
- hypoxanthin chemie MeSH
- hypoxanthiny chemie MeSH
- kyseliny fosforité chemie MeSH
- lidé MeSH
- nukleosidy chemie MeSH
- organofosfonáty chemická syntéza chemie metabolismus farmakologie MeSH
- prekurzory léčiv metabolismus MeSH
- techniky syntetické chemie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PURPOSE: Series of N,N-dimethylamino acid esters was synthesized to study their transdermal permeation-enhancing potency, biodegradability and reversibility of action. Effects of chirality, linking chain length and polyfluorination were investigated.
- MeSH
- adenin analogy a deriváty metabolismus MeSH
- alanin analogy a deriváty aplikace a dávkování farmakologie chemická syntéza MeSH
- aplikace kožní MeSH
- časové faktory MeSH
- elektrická impedance MeSH
- esterasy metabolismus MeSH
- farmaceutická chemie MeSH
- financování organizované MeSH
- halogenace MeSH
- hydrokortison metabolismus MeSH
- hydrolýza MeSH
- indomethacin metabolismus MeSH
- isomerie MeSH
- kapronáty aplikace a dávkování farmakologie chemická syntéza MeSH
- kožní absorpce účinky léků MeSH
- kůže metabolismus účinky léků MeSH
- methylaminy aplikace a dávkování farmakologie chemická syntéza MeSH
- molekulární struktura MeSH
- nosiče léků MeSH
- organofosfonáty metabolismus MeSH
- prasata MeSH
- příprava léků MeSH
- stabilita léku MeSH
- theofylin metabolismus MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
Adefovir (9-(2-phosphonomethoxyethyl)adenine) is an acyclic nucleoside phosphonate currently used for the treatment of hepatitis B. The aim of this study was to evaluate the effect of permeation enhancer DDAK (6-dimethylaminohexanoic acid dodecyl ester) on the transdermal and topical delivery of adefovir. In porcine skin, DDAK enhanced adefovir flux 42 times with maximum at pH 5.8 suggesting ion pair formation. DDAK increased thermodynamic activity and stratum corneum/vehicle distribution coefficient of adefovir, as well as it directly decreased the skin barrier resistance. Maximal flux was observed already at 2% adefovir+1% DDAK. The results were confirmed in freshly excised human skin where DDAK enhanced adefovir flux 179 times to 8.9 microg/cm(2)/h. This rate of percutaneous absorption would allow for reaching effective plasma concentrations. After the topical application, adefovir concentrated in the stratum corneum with low penetration into the deeper skin layers from either aqueous or isopropyl myristate vehicle without the enhancer. With 1% DDAK, adefovir concentrations in the viable epidermis and dermis were 33-61 times higher. These results offer an attractive alternative to established routes of administration of adefovir and other acyclic nucleoside phosphonates.
- MeSH
- adenin analogy a deriváty aplikace a dávkování chemie metabolismus MeSH
- antivirové látky chemie metabolismus MeSH
- aplikace kožní MeSH
- difuzní komory kultivační MeSH
- druhová specificita MeSH
- farmaceutická chemie MeSH
- farmaceutická vehikula chemie MeSH
- kapronáty farmakologie chemie MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- kožní absorpce účinky léků MeSH
- kůže metabolismus účinky léků MeSH
- lidé MeSH
- methylaminy farmakologie chemie MeSH
- organofosfonáty aplikace a dávkování chemie metabolismus MeSH
- permeabilita MeSH
- prasata MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- antidota farmakokinetika terapeutické užití MeSH
- benaktyzin terapeutické užití MeSH
- chemoprofylaxe MeSH
- cholinesterasové inhibitory * MeSH
- neurotransmiterové látky antagonisté a inhibitory MeSH
- organofosfonáty * metabolismus toxicita MeSH
- procyklidin terapeutické užití MeSH
- pyridostigmin-bromid terapeutické užití MeSH
- reaktivátory cholinesterasy * farmakokinetika terapeutické užití MeSH
- sorpční detoxikace MeSH
- trihexyfenidyl terapeutické užití MeSH
- Publikační typ
- práce podpořená grantem MeSH
